Protein purification process

Abstract

A method of purifying a target protein includes contacting a cell culture harvest or a protein preparation including at least one target protein with at least one fatty acid having 8 to 10 carbon atoms to form a mixture, contacting the mixture with one or more solids to form a mixture, the one or more solids comprise a cationic functional group, a metal binding functional group, or both, the metal binding functional group including a nitrogen-containing moiety selected from (1) a polyamine, (2) an imine, (3) an N-heterocycle, (4) an amino acid, (5) an N-hydroxyamide, (6), an arylamine, and combinations thereof, and separating solid materials after contacting the mixture with the one or more solids to provide a solution comprising the target protein.

What is claimed is: 
     
       1. A method of purifying an antibody comprising:
 (a) contacting a cell culture harvest or a protein preparation comprising at least one antibody with at least one fatty acid to form a mixture, wherein the at least one fatty acid is selected from enanthic (heptanoic) acid, caprylic (octanoic) acid, octenoic acid, pelargonic (nonanoic) acid, nonenoic acid, and capric (decanoic) acid; 
 (b) contacting the mixture with (i) one or more solid substrates comprising a metal binding functional group selected from the group consisting of tris(2-aminoethyl)amine, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, polypropylenimine tetramine, poly(amidoamine) (PAMAM) dendrimer, and deferoxamine (desferioxamine) and (ii) allantoin, wherein allantoin is present at a concentration in a range from about 0.6 to about 30% (w/v); and 
 (c) separating solid materials from the mixture to provide a solution comprising the antibody. 
 
     
     
       2. The method of  claim 1 , wherein a total amount of the one or more functionalized substrates is a volumetric proportion of the total volume of the preparation of from about 0.01% to about 20%. 
     
     
       3. The method of  claim 1 , wherein the at least one fatty acid and the one or more solid substrates are disposed in a single vessel or in a device, wherein the device optionally permits the passage of fluid while preventing the passage of solid materials therethrough. 
     
     
       4. The method of  claim 3 , wherein the device comprises a porous material selected from the group consisting of a membrane, a monolith, a woven material, a crystalline material, a gelatinous material, a column of packed particles, and combinations thereof. 
     
     
       5. The method of  claim 1 , wherein solid materials are removed by sedimentation, by sedimentation following centrifugation, by membrane filtration or by depth filtration. 
     
     
       6. The method of  claim 5 , wherein the membrane filtration or depth filtration comprises a contact surface that is functionalized. 
     
     
       7. The method of  claim 1 , wherein the cell culture harvest or protein preparation contains cells, and optionally resides in a bioreactor within which the cell culture harvest was generated. 
     
     
       8. The method of  claim 1 , wherein the at least one fatty acid comprises caprylic (octanoic) acid. 
     
     
       9. The method of  claim 1 , wherein the at least one fatty acid is present at a concentration in a range selected from the group consisting of: (a) from about 0.05 to about 5%, (b) from about 0.1 to about 1.0%, (c) from about 0.2 to about 0.4%, and (d) from about 0.1 to 0.2%. 
     
     
       10. The method of  claim 1 , wherein the mixture comprises a surfactant, wherein the surfactant is nonionic, zwitterionic, or cationic. 
     
     
       11. The method of  claim 10 , wherein the cationic surfactant comprises cetyltrimethylammonium bromide at a concentration ranging from about 0.001% to 0.05%, or from about 0.005% to 0.025%, from about 0.0075% to about 0.01%. 
     
     
       12. The method of  claim 1 , wherein the one or more solid substrates comprise tris(2-aminoethyl)amine. 
     
     
       13. A method for purifying an antibody comprising:
 (a) contacting a cell culture harvest or protein preparation with (i) at least one fatty acid having 8 to 10 carbon atoms, (ii) allantoin, at a concentration of up to about 30%, thereby forming a mixture, and (iii) at least one chemically functionalized solid or soluble substrate, wherein the at least one chemically functionalized solid comprises tris(2-aminoethyl)amine; and 
 (b) separating solid materials after the contacting to provide a solution comprising the antibody in a soluble form.